Chapter 8: Joints and Movement

Question 1

Classes of joints – you should be able to, given the name of a joint, classify it

Answer 1

Structural: Based on major connective tissue type that binds bones
Fibrous
Cartilaginous
Synovial

Functional: Based on degree of motion
Synarthrosis: Nonmovable
Amphiarthrosis: Slightly movable
Diarthrosis: Freely movable

Question 2

Cartilaginous joints – what is “synostosis”, why limited movement is important.

Answer 2

Cartilaginous joints unite two bones by means of either hyaline cartilage or fibrocartilage (table 8.1). Joints containing hyaline cartilage are called synchondroses; joints containing fibrocartilage are called symphyses.

Sutural ligament: two periostea plus dense, fibrous, connective tissue between. In adults may ossify completely: synostosis.

Question 3

Synovial joint – main elements and differences in relation to other joints in the body

Answer 3

Allow considerable movement

Most joints that unite bones of appendicular skeleton

Complex
Articular cartilage
Joint cavity and capsule
Synovial membrane and fluid

Bursae
Pockets of synovial fluid
Reduce friction
Bursae are found in the elbow, shoulder, hip and knee.
Bursitis

Question 4

Synovial fluid – components and characteristics

Answer 4

The best lubricant in the world

Composition: hyaluronan, lubricin, cells, proteins, glucose, etc.

In the synovial lining (synovium): fibroblasts*
and macrophages
MSC
White blood cells in
small amount
In disease, other cells like RBC, etc.

What does the synovial fluid and ketchup have in common??They are both thixotropic!

“viscosity decreases under continuous stress”

Question 5

Differences/similarities between tendons and ligaments

Answer 5

same in picture

Different:

Tendon: Muscle - Bone
Uniaxial forces
Lager fibrils
Less proteoglycans
Less collagen crosslinks
Higher % collagen type I
Lower % collagen type III

Ligament: Bone – Bone
Forces direction dependent on range of motion of joint
Slightly smaller fibrils
More proteoglycans
More collagen crosslinks
Lower % collagen type I
Higher % collagen type III

Question 6

Range of Motion: normal values for cervical flexion and rotation, factors that influence ROM

Answer 6

Amount of mobility demonstrated at a given joint

Types
Active
Passive

Influenced by
Shape of articular surfaces forming joint
Amount and shape of cartilage covering surfaces
Strength and location of ligaments and tendons
Location of muscles associated with joint
Strength of muscles associated with joint
Amount of fluid in and around joint
Amount of use/disuse of joint
Amount of pain in and around joint

Cervical flexion more than 45’

Cervical rotation more than 60’

Question 7

Rheumatoid arthritis

Answer 7

Rheumatoid Arthritis: Auto-immune disease

RA is an autoimmune disease of yet unknown cause.
There is no known cure for rheumatoid arthritis, treatment can be used to alleviate symptoms. Anti-rheumatic drugs, anti-inflammatory agents, analgesics
Treatments used to date:
Gold salts, apple diet, nutmeg, acupuncture, bee venom, extraction of teeth, fasting, honey, vitamins, exercise, insulin, magnets, cortisone injections, etc.
New drugs (Humira, Enbrel, etc.) – inhibition of TNF-α. Inflammatory cytokine. There are risks associated with this kind of drug.
After 5 years of diagnosis patients are not working anymore, after 10 years major disability.
Mind-Body connection: 75% of patients with RA develop depression (would you not?)

Question 8

Effect of aging on joints

Answer 8

Tissue repair slows
Production of synovial fluid declines
Ligaments and tendons become less flexible
Decrease in ROM (flexibility)
Menopause in women can aggravate